237 research outputs found
Intraguild predation between lady beetles and lacewings: outcomes and consequences vary with focal prey and arena of interaction
Citation: Noppe, Christophe, J. P. Michaud, and Patrick De Clercq. 2012. âIntraguild Predation Between Lady Beetles and Lacewings: Outcomes and Consequences Vary With Focal Prey and Arena of Interaction.â Annals of the Entomological Society of America 105 (4): 562â71. https://doi.org/10.1603/AN11165.We examined reciprocal intraguild predation (IGP) and cannibalism among various combinations of Coleomegilla maculata DeGeer and Chrysoperla carnea Stephens larvae as they developed feeding on greenbugs, Schizaphis graminum Rondani, on sorghum plants in microcosms. Pairs of C. maculata larvae suppressed aphids better than pairs of C. carnea larvae or heterospecific larval pairs and yielded the highest rate of plant survival. IGP by C. carnea larvae occurred mostly in the first instar, whereas C. maculata larvae were more aggressive in later instars. Although C. carnea was the superior intraguild predator, winning 62.7% of contests in microcosms, this value increased to 88.9% when the experiment was repeated in petri dishes without plant material, regardless of whether greenbugs or eggs of Ephestia kuehniella Zeller were offered as focal prey. Provision in petri
dishes of the sessile, higher quality prey (Ephestia) as opposed to greenbugs, improved the survival of solitary larvae and delayed cannibalism and IGP until later developmental stages in both species. Larvae of C. maculata that cannibalized took longer to develop and weighed less at pupation,
independent of the arena or prey offered. Although larvae of C. carnea did not pay a cost for cannibalism or IGP in microcosms, there were some negative developmental effects of IGP in petri dishes, particularly on the Ephestia diet. These results illustrate how the plant, as a substrate, can
mediate the strength of IGP interactions and how the relative suitability of the focal prey can influence both the timing and consequences of cannibalism and IGP
Metaheuristic methods applied to the environmentally conscious optimization of wood-plastic composite
This paper addresses the optimization of the quality of wood plastic composites(WPC) designed for outdoor uses such as decking, taking into account theenvironmental impact during the life cycle of the product, from production to end oflife. In a context where several conflicting objectives must be satisfied simultaneouslyin the design process, meta-heuristic approaches provide efficient methods foroptimization. Particle swarm optimization (PSO) has been chosen here to solve acomplex problem in which physical properties such as creep and duration of load,water absorption and swelling, need to be improved with a limited impact onenvironment. This requires to get reliable information on material properties as relatedto its composition, environmental impacts through life cycle analysis (LCA), and toimplement this information through analytical or probabilistic models in the PSOalgorithm in order to obtain a set of optimal solutions for the composite. This papershows the feasibility of this approach, which can be generalized in the design of anytype of composite structures, provided objective functions can be specified
Sediment reworking by marine benthic species from the Gullmar Fjord (Western Sweden): Importance of faunal biovolume
In order to compare and quantify sediment reworking activities by different species/functional groups of macrofauna, a laboratory experiment was carried out with species from the Gullmarsfjord (Western Sweden). Monospecific communities of Amphiura filiformis, Echinocardium cordatum, Scalibregma inflatum and Abra nitida were introduced in experimental mesocosms, with identical densities (795 ind. mâ2), for 10 days. Sediment reworking was studied by quantifying downward and upward movements of fluorescent inert tracers (luminophores). Luminophores with different colour were initially deposited both at the sediment surface and within the sediments. Population biomass and biovolume were also determined. Surface tracers reworking coefficients ranged from 0.6 to 2.2 cm2 yâ1 and 0.9 to 4.1 yâ1, respectively for the biodiffusive-like and non-local transports. Calculated biodiffusive-like coefficient was between 1.0 and 2.3 cm2 yâ1 for the deep tracers. For both tracers, the E. cordatum population presented the highest reworking coefficients. Among the morphological and/or ethological parameters that could determine overall patterns of reworking and differences between species, results have shown a direct relationship between the apparent biodiffusive mixing and the biovolume of the individuals (Db=0.35 â Biovolume). This suggests that the biovolume of macrofauna may allow a rough estimate of the biodiffusive-like reworking intensity of particles deposited on the sediment surface
Optimisation multi-objectifs de propriétés d'un matériau par essaim particulaire : application aux composites à base de bois
Lâoptimisation multi-objectifs, appliquĂ©e
aux propriétés d'un matériau, permet l'exploration de l'espace de recherche et
lâobtention dâun ensemble de solutions Pareto-optimales. Un espace de recherche Ă©tant
défini par des équations algébriques, des connaissances qualitatives et des algorithmes,
il peut ĂȘtre modĂ©lisĂ© dans un mĂȘme systĂšme d'optimisation par essaim particulaire. Nous
présenterons les principes de modélisation que nous illustrerons avec l'écoconception de
composite bois-plastique
Bilan et perspectives sur la gestion des eaux pluviales à la parcelle sur le territoire des Hauts-de-Seine Points forts, réticences et axes d'amélioration
National audienceIn 2005, the dĂ©partement' council of Hauts-de-Seine approved its sewer system master-plan for the next 15 years. In a highly urbanised context, the dĂ©partement conducts a voluntary policy for stormwater control aimed at reducing combined sewer overflow and the flooding risks. To improve the efficiency of its policy in the Hauts-de-Seine county, urban managers and sewer system owners' commitment is needed. Therefore, the dĂ©partement has developed several tools ta promote a consistent policy for sustainable stormwater management. After seven years, the dĂ©partement has wished ta initiate a review of its policy through a series of interviews of its partners: local authorities and developers. These interviews have shown that stormwater regulation rules are now included in most municipalities' sewer system regulation documents and land use plans. Although many new buildings and developments were exemplary, it seems that some reticence sometime remains about stormwater source control and also access in private estates for checking the stormwater collecting system. Continuing a strong and long-lasting policy as well as mproving stormwater source control will contribute to update our sewer system master-plan.En 2005, le conseil gĂ©nĂ©ral des Hauts-de-Seine approuvait son schĂ©ma dĂ©partemental d'assainissement (SDA) pour les 15 annĂ©es suivantes. Dans un contexte fortement urbanisĂ©, ce document dĂ©finit une politique en matiĂšre de maĂźtrise des eaux pluviales ayant pour objectif la protection des milieux naturels et la rĂ©duction des inondations par dĂ©bordement de rĂ©seaux. Conscient de la nĂ©cessitĂ© d'impliquer l'ensemble des acteurs de l'urbanisme et de l'assainissement pour garantir l'efficacitĂ© de sa politique sur le territoire des Hauts-de-Seine, le dĂ©partement a dĂ©veloppĂ© un panel d'outils pour promouvoir la cohĂ©rence des politiques relatives Ă la gestion durable des eaux pluviales. Aujourd'hui, Ă mi-parcours de la mise en oeuvre du SDA 2005-2020, le dĂ©partement a souhaitĂ© engager une dĂ©marche d'Ă©valuation de sa politique en menant une sĂ©rie d'entretiens auprĂšs de ses partenaires: collectivitĂ©s et amĂ©nageurs. Ces enquĂȘtes ont permis de mettre en Ă©vidence des rĂ©sultats concrets en matiĂšre d'intĂ©gration par les collectivitĂ©s des prescriptions de maĂźtrise des eaux pluviales dans les rĂšglements d'assainissement et les documents d'urbanisme et le dĂ©veloppement de plusieurs projets d'amĂ©nagement exemplaires, mais ont Ă©galement soulignĂ© l'existence persistante de nombreux freins pour une mise en oeuvre efficace des techniques alternatives et des contrĂŽles des ouvrages de gestion des eaux pluviales dans les parcelles privĂ©es. La poursuite d'une politique forte et pĂ©renne ainsi que l'esquisse de plusieurs propositions d'amĂ©lioration en matiĂšre de gestion des eaux pluviales alimenteront l'actualisation du SD
A Role for the RNA Chaperone Hfq in Controlling Adherent-Invasive Escherichia coli Colonization and Virulence
Adherent-invasive Escherichia coli (AIEC) has been linked with the onset and perpetuation of inflammatory bowel diseases. The AIEC strain LF82 was originally isolated from an ileal biopsy from a patient with Crohn's disease. The pathogenesis of LF82 results from its abnormal adherence to and subsequent invasion of the intestinal epithelium coupled with its ability to survive phagocytosis by macrophages once it has crossed the intestinal barrier. To gain further insight into AIEC pathogenesis we employed the nematode Caenorhabditis elegans as an in vivo infection model. We demonstrate that AIEC strain LF82 forms a persistent infection in C. elegans, thereby reducing the host lifespan significantly. This host killing phenotype was associated with massive bacterial colonization of the nematode intestine and damage to the intestinal epithelial surface. C. elegans killing was independent of known LF82 virulence determinants but was abolished by deletion of the LF82 hfq gene, which encodes an RNA chaperone involved in mediating posttranscriptional gene regulation by small non-coding RNAs. This finding reveals that important aspects of LF82 pathogenesis are controlled at the posttranscriptional level by riboregulation. The role of Hfq in LF82 virulence was independent of its function in regulating RpoS and RpoE activity. Further, LF82Îhfq mutants were non-motile, impaired in cell invasion and highly sensitive to various chemical stress conditions, reinforcing the multifaceted function of Hfq in mediating bacterial adaptation. This study highlights the usefulness of simple non-mammalian infection systems for the identification and analysis of bacterial virulence factors
European recommendations integrating genetic testing into multidisciplinary management of sudden cardiac death.
Sudden cardiac death (SCD) accounts for 10-20% of total mortality, i.e., one in five individuals will eventually die suddenly. Given the substantial genetic component of SCD in younger cases, postmortem genetic testing may be particularly useful in elucidating etiological factors in the cause of death in this subset. The identification of genes responsible for inherited cardiac diseases have led to the organization of cardiogenetic consultations in many countries worldwide. Expert recommendations are available, emphasizing the importance of genetic testing and appropriate information provision of affected individuals, as well as their relatives. However, the context of postmortem genetic testing raises some particular ethical, legal, and practical (including economic or financial) challenges. The Public and Professional Policy Committee of the European Society of Human Genetics (ESHG), together with international experts, developed recommendations on management of SCD after a workshop sponsored by the Brocher Foundation and ESHG in November 2016. These recommendations have been endorsed by the ESHG Board, the European Council of Legal Medicine, the European Society of Cardiology working group on myocardial and pericardial diseases, the ERN GUARD-HEART, and the Association for European Cardiovascular Pathology. They emphasize the importance of increasing the proportion of both medical and medicolegal autopsies and educating the professionals. Multidisciplinary collaboration is of utmost importance. Public funding should be allocated to reach these goals and allow public health evaluation
Towards the development of ecosystem-based indicators of mangroves functioning state in the context of the EU water framework directive
European Water Framework Directive is enforced in five tropical French Oversea Territories where mangroves are present. Developing bioindication tools to support the ecosystem-based management approach of the Directive is needed. A series of expert workshops was organized and led to the proposal of a strategy and of an applied research program to develop bioindication tools. The proceedings of the workshops are presented as a case study, as this is the first time such an integrative ecosystem-based approach is proposed in mangroves, combining structural and functional aspects, from forest structure to benthic community functioning
Modification of the aggregation behaviour of the environmental Ralstonia eutropha-like strain AE815 is reflected by both surface hydrophobicity and amplified fragment length polymorphism (AFLP) patterns
Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.
Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field
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